| abstract |
A gypsum slurry includes calcium sulfate hemihydrate, a set retarder in amounts of at least 0.15 lb/MSF, a set accelerator, water and aqueous foam. The set accelerator is selected to provide nucleation sites for crystallization of calcium sulfate dihydrate and is present in amounts of at least 5 Ib/MSF. The water to calcium sulfate hemihydrate ratio is at least 0.95. Further, aqueous foam is added in amounts sufficient to create a gypsum board having a dry density of about 29 to about 35 lbs/ft 3 . |